Autoamtic starter for internal-combustion engines



Dec. 22, 1953 WOLF 2,663,804

AUTOMATIC STARTER FOR INTERNAL-COMBUSTION ENGINES Filed May 2, 1950INVEN TOR.

Patented Dec. 22, 1953 AUTOMATIC STARTER FOR INTERNAL- COMBUSTIONENGINES Walter A. Wolf, Logansport, Ind., assignor to Switches, Inc.,Logansport, Ind., a corporation of Indiana Application May 2, 1950,Serial No. 159,526

6 Claims. 1

My invention relates to improvements in starter switches for internalcombustion engines.

More particularly, my invention relates to i1nprovements in the type ofstarter switches wherein an electromagnet energized by an engine drivengenerator, is relied upon to hold the starter switch in the open circuitposition when the engine is running.

In the prior art devices of this general class, it is essential that aminimum supply of energy sufiicient to operate the electromagnet beforthcoming from the generator both at idling and throughout the entirerange of operating engine speeds; otherwise, the switch will close toengage the starter mechanism. This frequently results in stripping theteeth from the flywheel of the engine or in other serious damage to thestarting mechanism. While in theory the generator may be set to deliverample energy at all engine speeds to disable the starter, and while thisperformance is usually obtained in the case of new equipment, suchfactors as loose generator belts, improper setting of the generator, andworn brushes, may cause the generator voltage output to drop at idlingand part throttle engine speeds to a level at which the electromagnetwill not hold the starter switch in the open position.

A cordingly, it is the principal object of my invention to provide astarter switch for internal combustion engines in which the switch isheld inoperative at idling and part throttle engine speeds, regardlessof the energy supplied by the generator to the electromagnetic device ofthe switch.

Another object of my invention is to provide a starter switch of thecharacter described which is easily to install, dependable in use, andin expensive to manufacture.

.To the end of achieving these objects, my iii- .vention, as installed,comprises (1) a switch for opening and closing the circuit of thestarter motor for the engine, (2) energy storing means such as a springurging the switch into the closed circuit position, (3) movable stopmeans normally resisting movement of the switch into the closed circuitposition, (4) means actuated by the engine throttle control, when the.latter sets the engine to operate at high speeds, for moving themovable stop means to allow movement of the switch into the closedcircuit position, and (5) electromagnetic means energized by the enginegenerator to prevent movement of said switch into the closed circuitposition, regardless of the position ofsa-id movable stop means, as

long as the engine is operating at medium and high speeds. In oneapplication of my invention the switch is placed directly in the circuitof the starter motor for the engine. In another application the switchserves as a relay for opening and closing a conventional solenoidstarter switch in the starter motor circuit.

In order that my invention may be more fully disclosed, reference is hadto the accompanying drawing which illustrates one form of apparatusembodying the foregoing and such other principles, advantages andcapabilities as may be pointed out as this description proceeds, or asare inherent in the present invention. For purposes of clarity inexposition, the following description is explicit and the accompanyingdrawing detailed, but it is distinctly to be understood that saidexposition is illustrative only, and that my invention is not restrictedto the particular details recited in the specification or shown in thedrawing.

In the drawing:

Figure l is a vertical cross sectional View of an automatic starterembodying my invention, an exemplary wiring diagram for use therewithbeing shown schematically;

Figure 2 is a vertical cross sectional view of the embodiment of Figure1, as it appears when set in the starting position; and

Figure 3 illustrates a second application of my invention, in which itserves as a control relay rather than as the primary starting switch.

Like reference characters designate like parts in the drawing and in thedescription of my invention which follows hereafter.

Referring now to the drawing, and more particularly Figures 1 and 2thereof, my automatic starter is'shown as including a casing ill, a par"tition H and an insulating plate 12 therein, and

two binding posts :2 and It extending on opposite sides from the casingill. The binding post i2 secures the contact H5 in place and isinsulated from the casing it by the insulating washers I4 and 45. Thelock washer ll and nuts l8, IBiasten the binding post 42 in place, andalso provide means for connecting said post l2 to a starter motor i9 ofan internal combustion engine through the wiring 29. Similarly, thebinding post 13 is insulated from the casing It by the insulatingwashers 22 and 21, and positions the contact 2! as shown. Lock washer 23and nuts 24, 24 fasten the post l3 in place, and provide means forconnecting the binding post 2 to a battery 25 or other source of energythrough the wiringit.

ascasoc 3 Extending downwardly from the partition ii plate i2 is asleeve 28, in which an armatur s slidable. The sleeve 28 supports acarrier ing spool so for the winding 3i of an eiejtroniagnet, designatedgenerally by the numoral One end of the electromagnet winding 3i isconnected through the binding post 3 and the wiring to the groundedgenerator 33, which is driven by the internal combustion engine. Theinsulating grommet 58 insulates the post 33 from the casing ill, whilethe nuts 52, 5?. both secure the post 3 in place and facilitateconnecting it to the generator 33. The other side of the electromagnetwinding 3! is connected to the partition it by the wiring 3t, and istherefore grounded to the casing iii. The electromagnet is so arrangedthat when the winding Si is energized by the generator 33, the armature29 is urged downwardly into'the position shown in Figure 1. A spring 3?fits within the bore 33 of the armature 2a, to urge said armatureupwardly to the position shown in Figure 2. A contact plate 39 issecured to the upper end of the armature 29, by the fastener it and thewasher ll, but is insulated from said armature 22! by the insulatingwashers 6B, 5i.

A bonnet is secured to the upper end of the casing it, and has a hangedopening i l therein. positioned in the upper portion of the casing it isan insulating plate #25 and a backing plate it, which are spaced fromthe bonnet by the spring fill. A plunger 38 extends through the flangedopening it and the bonnet :3, and through the opening es in the plates55 and it. A spring surrounds the plunger t8, and bears against theshoulder portion 5i thereof to urge the plunger it downwardly into theposition shown in Figure l. The spring so is purposely made strongerthan the spring 3?, so that when no external forces are exerted on theplunger 28, said plunger holds the armature 253 in the position ofFigure 1, against the opposition of the spring ill.

The casing is is secured to a bracket 52, whereby the device may beecured to an internal combustion engine. The end of the plunger 18 is inturn connected to the accelerator rod 53 of the engine, through thespring 5% and the clamp 55. By means of the fastener 55 and 5?, theclamp 55 may be and preferably is positioned on the accelerator rod sothat it is necessary to move the rod 53 to substantially the fullthrottle position, before the plunger i8 is moved against the oppositionof the spring 5? to the position shown in Figure 2.

The spring urging the shoulder portion 5% of the plunger it, forces thearmature 23 to the position of Figure l, by overpowering the spring Withthe armature 29 thus depressed, the contact plate St is spaced from thecontacts i5 and 2 i, so that no energy can flow from the battery '25 tothe starting motor !9.

When the accelerator rod 53 is actuated, as for example by fullydepressing the accelerator foot pedal, the spring is put under tension,and the plunger pulled from the position of Figure 1 to the position ofFigure 2. When this occurs, the spring 3? moves the armature 29upwardly, until the contact plate 35 bridges the contact i5 2i. Thiscompletes the circuit between the battery 25 and the starting motor as,whereupon the starting motor it cranks and starts the engine.

As soon as the engine starts, the normal reaction of the operator is toallow the accelerator foot pedal which controls the accelerator rod 53to return to the idling or part throttle position. The plunger isthereupon returns to the position of Figure l, and moves the contactplate 3d away from the contacts it and 2!, to open the circuit or" thestarter motor it. the same time, the engine drives the generator 33,which energizes the winding iii of the electromagnet 32. The strength ofthe magnetic field of the electromagnet 32 normally is sufiicient tomove the armature 29 downwardly against the resistance of the springiii. However, the starter switch does not rely upon the electromagnet 32to break the contact between the contacts is and 22 and the plate 35,since as the engine is started up, the plunger iii; makes positive thisaction. Thus, even though the output of the generator 33 at idling orpart throttle speed may be insui'llcient to cause the electromagnet toovercome the upward force of the spring 3?, the plunger insures that thecircuit of the starter motor iii remains open, so that motor it cannotengage the starting mechanism of the internal combustion engine.

As the engine is accelerated, by the movement or the accelerator rod 53,the spring 54 is pulled taut and moves the plunger is away from thecontact plate As the engine picks up speed, however, the output of thegenerator also increases, so that as the engine is turning at forexample one-half throttle, the generator is energizing the electromagnet32 sufficiently to easily overcome the resistance of the spring 3? andmaintain the armature 29 in the open circuit position of Figure 1.

It will be seen that my invention provides positive action means formaintaining the circult of the starting motor it open at all enginespeeds. At low speed the spring all is the principal force maintainingthe circuit or the motor i9 open, while as the speed of the engineincreases this function is assumed by the electromagnet 32. Thus at lowengine speeds, when the performance of the electromagnet 32 is leastdependable, and may even be insumcient to resist the upward force of thespring 3?, other means which operate independently or" the speed of theengine, are used to maintain the circuit of the starter motor it open.

While in the application of my invention illustrated in Figures 1 and 2,the contacts it and 2i and the contact plate 59 are placed directly inthe circuit of the starting motor it, in certain applications it may bedesirable to use my in vention in the manner of a relay, rather than asthe primary starter switch. When this is the case, the arrangement shownin Figure 3 may be used to advantage. More particularly, in thisapplication the binding post 52 is connected through the lead to thesolenoid post 63 of a conventional solenoid starter switch t l. Oneterminal 65 of the starter switch is connected to the starter motor isthrough the lead 6?, while the other terminal 58 of the switch E4 isconnected to the battery 25 or other source of electrical energy throughthe lead 69. Also connected to the battery 25 through the lead it is theother binding post it of my device. Since the current flowing to thebinding post it through the lead is substantially less than the startermotor current, it is practical to interpose the ignition switch it inthe lead it.

Using the circuit arrangement of Figure 3, when the plunger (is isextracted from the casing it, to close the contact plate 39 against theyer contacts it and. 2 I ,current flows from the battery 25ththesolenoid post 63, whereuponthe solenoid starter switch 64 closes thecircultibetween the startermotor l9 and the battery 25. As the in ternalcombustion engine starts up, the operaion of a plunger 48 and therelated apparatus within the casing I is the same as thatoutlined-abovein connection withFi'gures .1 and 2. The only difierence between thearrangement of Figures 1 and 2 and that of Figure 3 is therefore one ofapplication rather than principle of :operatiomin the first instancemyinvention-being used asiaiprimary starter switch,:whereas in thesecond instance it serves as a relay which :actuates the primary starterswitch.

:Having thus fully disclosedzmy novel automatic starter for internalcombustion engines, and illustrated its utilitybyreferenceto certainspecific applications thereof, I claim as my invention:

1. A starter for the starterxmotor of aninternal combustion engineincluding a throttle control, a generator driven by sa d engine, and asource of electrical energy for said starter motor, said startercomprising; a casing, an electromagnet mounted in said casingelectrically connected to said generator as the latter is driven by saidengine, a first switch contact connected to said starter motor, a secondswitch contact connected to said source of electrical energy, anarmature in said electromagnet and including a contact member forbridging said first and second switch contacts, said armature beingoperated by said electromagnet to open said switch contacts uponenergizing said electromagnet, a first spring urging said armature toclose said switch contacts, a plunger slidable in said casing andpositioned for engagement of said armature, an end of said plungerextending through said casing, a second spring, said second spring beingstronger than said first spring and engaging said plunger to move saidplunger into engagement with said armature to open said switch contacts,and a coil spring interconnecting the outer end of said plunger and saidthrottle control, tensioning of said coil spring moving said plungeragainst the resistance of said second spring to permit movement of saidcontact member to bridge said switch contacts, the strength and initialtensioning of said coil spring being such that the resistance of saidsecond spring is not overcome until said throttle control is in thesubstantially fully open position, whereby at idling and low enginespeeds said second spring is operative to maintain said switch contactsopen independent of the influence of said electromagnet on saidarmature.

2. A starter for the starter motor of an internal combustion engineincluding a throttle control, a generator driven by said engine, and asource of electrical energy for said starter motor, said startercomprising: a casing, an electromagnet mounted in said casing andelectrically connected to said generator as the latter is driven by saidengine, a first switch contact connected to said starter motor, a secondswitch contact connected to said source of electrical energy, anarmature in said electromagnet and including a contact member forbridging said first and second switch contacts, said armature beingoperated by said electromagnet to open said switch contacts uponenergizing said electromagnet, a first spring urging said armature toclose said switch contacts, a plunger slidable in said casing andpositioned for engagement of said armature, a second spring, said secondspring stronger than said first spring -an'd engaging said plunger tomove said'armature to open'said switch contacts, and

means interconnecting said plunger and said throttlecontrol'forovercoming the resistance of said'second'spring when saidthrottle control is substantially fully opened, to permit movement ofsaid armature to close said switch contacts. whereby'at idling and lowengine speeds said second spring is operative to maintain said switchcontacts open independent of the influence of said electromagnet on saidarmature.

'3. A starter control for internal combustion engines including athrottle control, a generator driven. by said engine, a starter motorand a source of electrical. energy, said starter control comprising anelectrical connection including a switcliibetween said-starter motor andsaidsource of electrical energy, said switch comprising a movablecontact plate for opening and closing said switch, an electromagnetconnected to said generatonian armature in said electro-magnet, saidcontact plate being connected to one end of sai'd armaturc, sai'darmature being operated by said electromagnet when the latter isenergized to'move said contact plate to open said switch, a

first spring engaging said armature to move the same to close theswitch, a plunger movable to engage one end of said armature, a secondspring stronger than the first spring engaging said plun ger forshifting the same for opening said switch against the pressure of thefirst spring, a coil spring connecting the outer end of said plungerwith said throttle control, the strength and initial tensioning of saidcoil spring being such that said throttle control must be substantiallyfully opened to move said plunger out of contact with said armature.

4. An automatic starter for internal combustion engines including athrottle control, a generator driven by the engine, a starter motor anda source of energy; said starter comprising a circuit connecting saidstarter motor and source or energy, a switch in said circuit having amovable contact plate for opening and closing said switch, means formoving said plate for controlling said switch, energy storing meansacting upon said contact plate moving means for closing said switch,movable stop means normally resisting movement of said contact platemoving means to switch closing position, means connected to saidthrottle control for moving said movable stop means to allow movement ofsaid contact plate to switch closing position when said throttle controlis in substantially full open position, and electromagnet meansconnected to said generator and energized thereby when said generator isdriven by the engine, for operating said contact plate moving meansagainst the opposition of said energy storing means to position saidcontact plate in switch open position.

5. An automatic starter for internal combustion engines including athrottle control, a generator driven by said engine, a starter motor anda source of electrical energy, means for electrically connecting saidstarter motor and source of electrical energy including a switch havingspaced switch contacts and a movable contact plate, an armatureconnected to said plate contact, a spring engaging said armature forurging same for moving said plate for closing said switch, anelectromagnet surrounding said armature and electrically connected tosaid generator and normally eiiective for moving said armature foropening said switch, a casing surrounding said starter, a plunger insaid casing and connected o if to said throttle, and a spring fornormally urging said plunger for engaging said armature for opening saidswitch, said last named spring overcoming the tension of the firstmentioned spring.

6. fhe combination with an ignition fired combustion engine including anelectric cranking motor, a, power generator driven by said engine, and amechanical accelerator for said engine, of a switch for controlling anenergized circuit for said cranking motor, which switch comprises a pairof contacts, a member movable toward and away from position foroperating said contacts, a first spring for urging said member towardsaid position, an electromagnet included in a circuit which is connectedto said power generator for moving said member away from said position,an armature in and operated by'said electromagnet for overcoming saidfirst spring, a second spring for also urging said member away from saidposition and independently capable of overcoming said first spring, anda third spring operated by said mechanical accelerator for neutralizingsaid second spring coincident with engine acceleration.

WALTER A. WOLF.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber

